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Stone chondrite 3.2/3.3 (S1,W5)
Description and references: Many stones weighing 204 g were found in the Dhofar region of Oman.
Mineralogy and classification (M. Ivanova, Vernad; L. Taylor, UTenn): the
meteorite consists of chondrules, 0.08-3.2 mm in diameter, (0.86 mm in
average) of different types, PO, POP, BO, RP, CC, and their fragments
embedded in a fine-grained matrix. Chondrule/matrix ratio is 1.1. Olivine
and low-Ca pyroxene have large compositional ranges: olivine has Fa1-50, CaO - 0.2 wt%; Al2O3 - 0.06 wt.%, Cr2O3 - 0.09 wt.%, PMD of Fa - 42%;
low-Ca pyroxene is Wo2-3.5En53-95; chondrules contain glassy mesostasis.
Accessory minerals include: pigeonite, chromite, troilite, rare hydroxides
and essentially rare FeNi metal (Ni 5 wt%; Co 0.4 wt%). Thermoluminescence
studies (A. I. Ivliev, Vernad) reveal petrological type 3.2/3.3. The
meteorite is heavily weathered, some silicates are altered. Weathering
grade is W5; shock stage is S1. Oxygen isotopic compositions (R. N.
Clayton, UChi): d18O = +8.56‰; d17O = +4.96‰ are unusual for chondrites.
Based on very low abundance of FeNi metal and hydroxides, and sizes of chondrules this unequilibrated ordinary chondrite can be preliminary
classified as LL chondrite.
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